1. Field of the Invention
The present invention relates to a system and method for utilizing resources in a communication system.
2. Description of the Related Art
Future-generation communication systems are under development to provide high-speed large data transmission/reception services to Mobile Stations (MSs). To accommodate more MSs, they are generally designed in the form of sectorized cellular communication systems (hereinafter, referred to as sectorized cellular communication systems).
A cell is sectorized by using directional antennas with a predetermined beamwidth, usually 120°, 90° or 60° in a Base Station (BS). Theoretically, if the sectors of the cell are mutually orthogonal, the system capacity increases by three, four, and six times for the respective sectorization angles. In practice, however, the beam patterns of the directional antennas, namely sectorized antennas overlap, rendering the sectors non-orthogonal. Therefore, the contribution of the cell sectorization to the system capacity is limited.
A major future-generation communication system is an Institute of Electrical and Electronics Engineers (IEEE) 802.16e communication system based on Orthogonal Frequency Division Multiplexing (OFDM). The IEEE 802.16e communication system is sectorized cellular communication systems. It seeks to fully utilize frequency resources in a cell by using ⅓ or less of the frequency resources for each sector. Compared to Code Division Multiple Access (CDMA), an OFDM sectorized cellular communication system such as the IEEE 802.16e suffers from interference among MSs to which the same frequency resources are allocated within a cell. Especially inter-sector interference affects performance degradation of MSs more adversely than inter-cell interference. Typically, the OFDM sectorized cellular communication system divides frequency resources for allocation to the sectors so that they are orthogonal in order to prevent the intra-cell interference. With the limitation of frequency resource allocation for no inter-sector interference on system design, an actual increase in the system capacity that can be achieved through cell sectorization does not approach a theoretical system capacity increase from cell sectorization.